原畅 王双蕾 陈嘉言 张鑫倪 宋彦涛

摘要 [目的]研究干旱胁迫对多根葱种子萌发和幼苗生长的影响。[方法]干旱是限制草原植物种子萌发的主要条件之一。以克氏针茅典型草原的多根葱种子为研究对象，采用纸上发芽法，用不同浓度的PEG6000模拟干旱胁迫培育种子，研究了不同梯度干旱胁迫对多根葱种子发芽率、活力指数、胚根、胚芽等指标的影响。[结果]PEG对多根葱种子萌发和幼苗生长具有显著影响，随着PEG浓度的增加，发芽速度、发芽率、发芽指数、活力指数、胚根与胚芽的长度、胚根的干重逐渐降低，而胚芽干重变化不明显。多根葱能在0-5%PEG干旱条件下较好的萌发和生长，PEG浓度大于10%，多根葱萌发和幼苗生长受到明显抑制。[结论]该研究可为干旱胁迫下多根葱种子的萌发提供指导。

关键词 多根葱；干旱胁迫；发芽率；发芽特性

Effect of Drought Stress on Seed Germination and Seedling Growth of Allium polyrhizum

YUAN Chang， WANG Shuang-lei，CHEN Jia-yan， SONG Yan-tao* et al （College of Environment and Bioresources， Dalian Minzu University， Dalian，Liaoning 116600）

Abstract [Objective]To study effect of drought stress on seed germination and seedling growth of Allium polyrhizum .[Method]Drought is one of the main factors for limiting the seed germination of grassland plants. Taking the Allium polyrhizum seeds from the Stipa Krylovii steppe as research object， the germination percentage，vigor index，radicle，embryo of A. polyrhizum seeds were tested on filter paper under different concentrations of PEG6000 to simulate the drought stress.[Result]PEG had significant effects on the seed germination and seedling growth， the indexes reduced gradually with the increase of PEG concentration， such as germination speed，germination rate， germination index， vigor index， the length of radicle and embryo， dry weight of radicle， but the dry weight of embryo was not significant. A. polyrhizum germinated and grew normally under the drought condition of 0-5%PEG， the germination and seedling growth of A. polyrhizum was significantly inhibited when the PEG concentrations was greater than 10%.[Conclusion]The research can offer guidance for A. polyrhizum seedling germination under drought stress.

Key words Allium polyrhizum；Drought stress；Germination rate；Germination characteristics

种子的自身结构及环境因素对其萌发有着重要作用，并最终影响到草原植被的形成及演替[1]。关于植物萌发的生态学研究，已有资料涉及温度、光照、盐分等环境因子对碱蓬、梭梭、沙地樟子松等多种植物萌发的影响[2-4]。研究表明，种子萌发是各种生态因子互作的产物，但萌发对生态因子的响应程度因物种和物种生态型的不同而異[5]。在内蒙古呼伦贝尔新巴尔虎右旗克氏针茅草原，干旱是该区域草原植被生长的重要限制因子之一[6]。研究发现克氏针茅占优势的典型草原逐渐退化为多根葱（Allium polyrhizum）占优势，但具体原因有待进一步探明[7]。……